Newegg offers the refurbished Western Digital Caviar Green 2TB Serial ATA 3Gb/s 3.5" Internal Hard Drive, model no. WD20EADS, for $59.99 with free shipping. That's the lowest total price we could find for a refurb by $18. This drive is purportedly cooler, quieter, and consumes up to 40% less energy than standard mechanical drives. It features a 32MB cache.

Note: A 90-day warranty applies, although it's unclear who supports it.